In general, various types of safety devices are provided in an automobile in order to protect passengers when a collision accident occurs. A representative example is an airbag that is inflated by gas so as to produce a cushion force for protecting the passengers.
After a controller such as an electronic control unit (ECU) and an airbag control unit (ACU) determines whether or not an automobile collision occurs by using a signal outputted from an impact detection sensor that detects an automobile collision, the controller carries out a safing logic operation to deploy the airbag when the controller determines that the automobile collision is so serious that the airbag needs to be deployed.
The safing logic operation is a logic operation that is performed when an output of a sensor exceeds a set minimum value in order to check whether or not the automobile collision actually occurs. With respect to the existing safing logic operation, there are the first case in which the safing logic operation is performed when an output value of a main sensor provided at the controller is equal to or greater than a set critical value, and the second case in which the safing logic operation is performed when an output value of the impact detection sensor is equal to or greater than a set critical value.
However, because the existing safing logic operation is performed after the automobile collision occurs even though any one of the two cases is applicable, there is likelihood that the deployment time of the airbag may be delayed.